KR20120043658A - Piping system - Google Patents

Abstract

PURPOSE: A piping system is provided to reduce a load applied to an equipment nozzle because a spring reaction force is compensated through a movement of a bellows generated by an expansion of a piping member. CONSTITUTION: A piping system comprises a bellows type expansion joint, a main pipe(1), first and second and a third pipe members(5,7,9), first and second tie rod support members(10,11), a tie rod(12), an anchor(13). The bellows type expansion joint is connected to inside of an equipment nozzle(6). The first pipe member is connected to the equipment nozzle and connected to one end of the main pipe through a first bellows(4). The other end of the second pipe member is connected to the side portion of the main pipe. The third pipe member is connected to the other end of the second pipe member through a second bellows(8). The first and second tie rod support members are fixed around each outer side of the first and third members. The tie rod maintains a constant gap between the first and second tie rod support members. The anchor sets a part of the main pipe near the first bellows as a fixed point.

Description

Piping System {PIPING SYSTEM}

The present invention relates to a piping system connected to the equipment of a petrochemical plant or a power plant. The equipment is a rotary machine, such as an expander of a fluidized catalytic cracker (FCC) or a high-temperature reactor, with a small allowable load on the pipe component.

Since the inflator of the FCC has a precision rotation mechanism, any excessive force or moment must be prevented from being applied to this type of equipment. Therefore, in the metal piping system connected in the equipment nozzle installed in such equipment, measures are taken to reduce the load on the nozzle.

One conventional measure is to install several tiered expansion joints installed in the piping system to absorb the movement caused by the thermal expansion of the pipes and the thermal movement of the equipment nozzles during the operation of the facility. . As the expansion joints, bellows expansion expansion joints including bellows (see JIS B 2352) are generally known. Table 1 of JIS B 2352 shows several types of bellows type expansion joints. Applying the simplest untied bellows-stretch joint between these pipes to connect the pipes together is axial movement, axis-vertical movement and angular of any plane pipe except twist. ) Makes it possible to absorb the movement. As a result, the load on the nozzle can be reduced by converting a large force due to the bending of the pipe into a small force due to the bending of the bellows.

However, in this type of joint, the force generated by the internal pressure in the bellows (hereafter the internal pressure thrust) is applied to the equipment nozzle in the direction of separating the pipes from each other (or in the direction of pulling each other). This makes it difficult to apply a simple non-knotted bellows expansion joint when the pipe bore or internal pressure is increased. In this case, a knotted bellows-type telescopic joint is used, which includes a mechanism for limiting the axial extension of the bellows so as not to transmit internal pressure thrust outside the bellows. A well-known type of knotted bellows expansion joint is a hinge type expansion joint that absorbs only angular movement in one plane by using a hinge at the pipe end connected through the bellows, any movement as well as angular movement in one plane. Gimbal type telescopic joints that also absorb angular movement in the plane, and universal telescopic joints that absorb axial-vertical movement in any plane (see JP10-141565A).

As the piping system moves vertically due to the thermal expansion of each piping member, a special pipe support device is needed to support the piping weight with subsequent vertical movement. For this purpose, the piping system is installed in the lifting state by the use of various spring hangers or constant spring hangers with mechanisms for alleviating load changes due to movement.

A bellows type telescopic joint usage for absorbing axial movement without transmission of internal pressure thrust outside the bellows type telescopic joint, further comprising a tie rod disposed to allow axial movement in equilibrium and a bellows to offset internal pressure thrust. A pressure balanced bellows type expansion joint is used (see FIG. 8 of JP10-141565A or the drawing of US Patent No. 4265472).

As described above, in conventional piping systems that include several knotted bellows-stretched joints, the load on the equipment nozzle can be reduced. However, this load mitigation measure is becoming insufficient due to the recent trend of large capacity of the plant.

As the pipe size increases as the plant grows, the internal pressure thrust on the bellows is greater, and the spring constant of the bellows itself increases. In addition, the pipes are longer, and therefore the movements absorbed are also greater. Friction forces on sliding parts such as hinges and gimbals increase and cause an increase in the load on the machine nozzle. The spring hanger support also frictions the sliding portion and the spring itself, and reaction forces are generated during the movement. This force is called the load of initial movement and is approximately 5% of the supporting load. Therefore, the influence of the force on the spring hanger support on the equipment nozzle can no longer be ignored. For example, for a stainless steel pipe with a diameter of Ø3,500 millimeters and a thickness of 135 millimeters, the pipe weight is 11 tonnes per meter. When a 14 meter pipe is supported by the spring hanger support on the equipment nozzle, the total pipe weight is 150 tons and the initial moving load reaches about 7.5 tons. As a result, this load becomes remarkable, exceeding the load tolerance of the equipment nozzle.

Pressure balanced bellows-type telescopic joints are fitted with machine nozzles to prevent various loads, including internal pressure thrust, spring reaction forces, and frictional forces of the piping system, and the operating resistance of the hanger support against the machine nozzles. It has been considered in the conceptual basis how to set a fixed point (anchor) as close as possible to the bellows of the piping member to install between the members and to fix the piping system. This anchor prevents any piping loads, friction and reaction forces transmitted from the other side of the anchor to the equipment nozzle side by firmly supporting the piping. However, in the prior art, this method was very difficult for the following reason.

In this situation, internal pressure thrust and spring reaction forces due to the movement of the bellows are applied to the machine nozzle. Internal pressure thrust can be absorbed by using the above described pressure balanced bellows type expansion joint. However, when the piping member close to the bellows is fixed, thermal expansion of all axes in the equipment nozzle must be absorbed by the compression movement of the bellows. When a pressure balanced bellows type expansion joint is used, the pipe diameter is enlarged to increase the spring constant of the single bellows, and the effect of the additional pressure balanced bellows further increases the spring constant. As a result, the spring reaction force increases and the load on the equipment nozzle exceeds the allowable value, making it impractical to install the anchor in the piping member close to the bellows in the scope of the prior art. Therefore, it is urgently necessary to achieve a method of installing an anchor in a piping member close to the bellows by developing a pressure balanced expansion joint with a new technique. This is to balance the spring reaction force of the balance bellows and the spring reaction force of the main bellows by thermal movement in the piping piece in the expansion joint system by moving in the machine nozzle.

The present invention has been developed in view of the problems of the background art, and an object of the present invention is to provide a piping system capable of reducing the load on the equipment nozzle with reliability even when the pipe diameter is enlarged due to the recent trend of increasing the plant capacity. It is.

According to an aspect of the present invention, a piping system comprises: a bellows type telescopic joint connected within an equipment nozzle of the equipment; Main pipe; A first pipe member connected to an equipment nozzle extending from the equipment and connected to one end of the main pipe through a first bellows; A second pipe member, one end of which is connected to the side portion of the main pipe; A third pipe member connected to the other end of the second pipe member through a second bellows; A first tie rod support member (flange) fixed around the outside of the first pipe member; A second tie rod support member (flange) fixed around the outside of the third pipe member; A tie rod for maintaining a fixed distance between the first tie rod support member and the second tie rod support member; And an anchor disposed to set the main pipe portion near the first bellows as a fixed point.

In this case, the length of the pipe member between the first tie rod support member and the second tie rod support member is determined to be thermal in the pipe nozzle of the main pipe closer to the equipment nozzle, the first pipe member, and the equipment nozzle than the anchor. Due to the movement, the first bellows contracts, the second bellows contracts, and moves (shrinkage amount) in the same manner as the first bellows by thermal expansion of all pipe members between the first and second tie rod support members.

This configuration uses a pressure balanced bellows type expansion joint structure. Therefore, the internal pressure thrust generated by the internal pressure can be balanced by the first bellows and the second bellows. The length of each piping member between the first tie rod support member and the second tie rod support member is adjusted, and both bellows are always set to have the same shrinkage movement with respect to the thermal expansion of the equipment nozzle and all the piping members. As a result, the spring reaction force of the bellows is canceled out.

Therefore, according to the present invention, in a piping system connected to a pipe that is heavier than the equipment nozzle and undergoes thermal expansion (or thermal contraction) due to the temperature of the internal fluid, the load on the equipment can be reduced. Compared to the conventional design method where conventional hinged telescopic joints, gimbal telescopic joints and universal telescopic joints are used, the anchor set is installed close to the nozzle, which significantly reduces the friction or operating resistance applied to the machine nozzle in the piping system. Can be. Furthermore, the spring reaction force of the bellows is canceled by using the bellows movement caused by the thermal expansion of the piping member of the piping system, thus significantly reducing the load on the machine nozzle than using conventional pressure balanced expansion joints. Can be.

These and other objects, features, and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings, which illustrate examples of the present invention.

1 is a side view schematically showing a piping system according to an exemplary embodiment of the present invention;
2 is a side view showing a piping system according to another exemplary embodiment of the present invention; And
3 is a side view illustrating a piping system according to another exemplary embodiment of the present invention.

The piping system according to the invention uses a bellows type expansion joint to which a pressure balance method is applied. 1 is a side view schematically illustrating a piping system according to an exemplary embodiment. As shown, the lower end of the piping system is connected to an equipment nozzle, such as a rotary machine, the piping system having an external force acting on the equipment nozzle (pipe self weight, thermal expansion of the pipe, spring reaction force of the bellows, internal Pressure thrust, load at different locations, frictional force or operating resistance).

1 shows an example in which a pipe extending in the horizontal direction is connected in the equipment nozzle. According to FIG. 1, the elbow pipe (curved pipe 1) has an injection end 2 and an discharge end 3. The discharge end 3 of the elbow pipe 1 is connected to a pipe extending in the horizontal direction. The injection end 2 of the elbow pipe 1 is connected to the upright pipe 5 via the bellows 4. The upright pipe 5 is connected to the equipment nozzle 6.

At the surface of the arc portion of the elbow pipe 1, the upright pipe 7 is welded to be continuous with the upright pipe portion of the elbow pipe 1. The upright pipe 7 communicates with the interior of the elbow pipe 1. The upright pipe 7 and the elbow pipe 1 have the same diameter. In order to match the temperature of the upright pipe 7 with the temperature of the elbow pipe 1, the opening of the communication site is preferably formed large, so that a fluid having a certain temperature can sufficiently flow into the upright pipe 7. . Thus, the elbow of the elbow pipe 1 can be replaced with a tee. The upright pipe 9 is connected to the end of the upright pipe 7 opposite the elbow pipe 1 via a bellows 8 having the same diameter as the bellows 4. The upright pipes 5, 9 each comprise a tie rod support flange 10, 11. The two tie rod support flanges 10, 11 are connected to each other by a plurality of tie rods 12 arranged at equal intervals and the same length. The flange is taken as an example of the tie rod support member in this exemplary embodiment. However, the tie rod support member is not limited to the flange. Other support units may also be applied.

The upright pipe portion of the elbow pipe 1 close to the bellows 4 is connected to the anchor 13. This joint does not move under any external force (ie, a fixed point). The anchor 13 is made of plate material and welded to the elbow pipe 1. The attachment site of the anchor 13 is fixed to a shaped-steel structure directly fixed to the concrete base on which the equipment 14 is installed. The equipment 14 is fixed so as not to move under any external force. The fixed point 15 of the machine and the anchor of the piping system (fixed point 13) are the base points of thermal expansion of the machine nozzle and piping system, respectively. However, while the reference point is on a straight line perpendicular to the installation surface of the equipment 14, this reference point does not necessarily have to be at the center line of the equipment nozzle 6 shown in FIG.

As described above, the bellows 4 is disposed between the equipment nozzle 6 and the elbow pipe 1 connected to the equipment nozzle 6 and the elbow pipe 1 portion as close as possible to the bellows 4 during manufacture. Is set to a fixed point by use of the anchor 13. Therefore, the shrinkage (ie spring reaction force) of the bellows 4 is reduced as much as possible while preventing the external force of the piping system from directly acting on the equipment. Areas as close as possible to the bellows 4 during manufacture are, for example, 4 mm thicker than the thickness of the production pipe from the connection ends (welding lines) of the bellows 4 and the elbow pipe 1, taking into account thermal effects or other restrictions in installation. Can be suitably determined from ˜5 times greater distance.

In the piping system, an axial internal-pressure thrust is applied to both ends of the bellows 4 due to the pressure of the fluid (pipe internal pressure) passing through the elbow pipe 1. The spring reaction force generated by the movement of the bellows 4 and the bellows 8 is applied to the equipment nozzle 6 when each piping member is thermally extended. However, when internal pressure thrust is applied to the bellows 4, the internal pressure thrust is also applied to the bellows 8. The downward internal pressure thrust of the bellows 4 is transmitted to the upright pipe 5 while the upward internal pressure thrust of the bellows 8 is transmitted to the upright pipe 9. However, since the upright pipes 5, 9 are connected to each other by tie rods 12, both internal pressure thrusts cancel each other out. Therefore, the internal pressure thrust of the bellows is not applied to the equipment nozzle 6.

For ease of understanding, the movement due to thermal expansion between the upper end of the tie rod support flange 10 and the lower end of the tie rod support flange 11 is not considered. Then, the bellows 4 contracts against the thermal movement of the equipment nozzle 6 while the bellows 8 extends in the same amount, so that the spring reaction force of the bellows generated by this movement is It is applied to the equipment nozzle 6 in the same direction.

The present invention uses the following design approach so that no load is applied to the equipment nozzle 6 by offsetting the spring reaction forces of the bellows 4, 8 generated by the movement.

First, thermal expansion from the equipment nozzle 6 to the anchor 13 is irradiated. With respect to the thermal expansion of the member nozzle 6, the upright pipe 5, and the member on the part of the elbow part 1 under the anchor 13 of the elbow pipe 1, since the anchor 13 is fixed, the bellows (4) shrinks and absorbs thermal expansion by all members. Next, thermal expansion between the tie rod support flanges 10 and 11 is investigated. The member between the tie rod support flanges 10, 11 moves up in full while the length is maintained by thermal expansion of the equipment nozzle 6. Since it is held between these parts by tie rods 12, the bellows 4 and the bellows 8 contract and tie rods of the elbow pipe 1, upright pipe 7, upright pipe 5 The thermal expansion of the member close to the elbow pipe 1 from the support flange 10 and the member close to the upright pipe 7 from the tie rod support flange 11 of the upright pipe 9 is absorbed.

The shrinkage amount of the bellows 4 is determined based on the presence of the anchor 13 of the elbow pipe 1. The amount of shrinkage of the bellows 8 is determined by the amount of remaining shrinkage between the tie rod support flanges 10, 11. The distance LT0 between the tie rod flanges 10 and 11 is sufficiently long, so that the movement of the bellows 8 in the shrinking direction due to thermal expansion between the tie rod flanges is also larger than the movement in the equipment nozzle 6. In addition, if the distance LT0 is sufficiently adjusted by the exact calculation of thermal expansion, the spring reaction force and the contraction amount by the bellows 4 and the bellows 8 can be the same, so that the spring reaction by the bellows 4 and the bellows 8 is achieved. The forces can be equalized. As a result, the spring reaction force of the bellows is not applied to the equipment nozzle 6 even if the equipment nozzle 6 is moved.

1 shows the parameters used in the formula, which are added to the configuration of the piping system according to the present exemplary embodiment. The outline of the design parameters is as follows:

D1: Movement amount [mm] due to the temperature change of the equipment nozzle (the direction of the tie rod support flange 10 seen from the equipment nozzle 6 is positive)

L1: Length of the part from the connecting end of the equipment nozzle 6 and the upright pipe 5 to the end of the tie rod support flange 10 opposite the equipment nozzle 6 [mm]

LT0: length of the tie rod 12 between the end of the tie rod support flange 10 opposite the equipment nozzle 6 and the end of the tie rod support flange 11 opposite the equipment nozzle 6 [mm]

LT1: Length from end of upright pipe 5 opposite equipment nozzle 6 of tie rod support flange 10 to the connecting end of bellows 4 and upright pipe 5 [mm]

LB1: Length of the axis of the bellows 4 [mm]

ΔLB1: amount of movement of the axis of the bellows 4 [millimeter] (the direction of contraction is positive)

LT2: Length of the elbow pipe 1 part from the connecting end of the bellows 4 and the elbow pipe 1 to the fixed point (anchor 13) [mm]

LT3: Length of the pipe part from the fixed point (anchor 13) to the connecting end of the upright pipe 7 and the bellows 8 [mm]

LB2: Length of the axis of the bellows 8 [mm]

ΔLB2: amount of movement of the axis of the bellows 8 [mm] (the shrinkage direction is positive)

LT4: Length of the upright pipe 9 portion from the connection end of the bellows 8 and the upright pipe 9 to the end of the tie rod support flange 11 on the equipment nozzle 6 side [mm]

α _(t) : Coefficient of thermal expansion of piping member when ambient temperature changes to t ℃

k _{(B1, t)} : spring constant at t ° C. temperature of bellows (N) [N / mm]

k _{(B2, t)} : spring constant at t ° C. temperature of bellows (N) [N / mm]

The formula used for the design of the piping system is as follows.

In Fig. 1, the thermal expansion from the fixed point (anchor 15) of the equipment to the fixed point (anchor 13) is calculated. The amount of movement of the bellows 4 by adding the amount of movement due to thermal expansion of the pipe portion from the equipment nozzle to the anchor point of the anchor 13 to the thermal expansion of the equipment nozzle 6 at the fixed point of the equipment (anchor 15) ( Contraction) ΔLB1 is calculated. Therefore, the following equation 1 is established.

In Equation 1, assuming that the temperature distribution is uniform and that the materials are similar in the piping system, the movement due to thermal expansion of each pipe portion is calculated by the coefficient of thermal expansion α _(t) at the same temperature. However, when the temperature and material differ from one pipe site to the other pipe site, the coefficient of thermal expansion must be changed for each pipe site to calculate.

In FIG. 1, when it is assumed that the temperature of the tie rod does not change, between the end of the tie rod support flange 10 opposite the machine nozzle 6 and the end of the tie rod support flange 11 on the side of the machine nozzle 6. The length LT0 of the tie rod 12 is fixed irrespective of the temperature change in other pipe parts. The sum of the movements due to thermal expansion of all the pipe portions therebetween is equal to the sum of the movements of the bellows 4 and the bellows 8 (shrinkage amount). Therefore, the following equation (2) is established.

Assuming that the spring constants of the bellows 4 and the bellows 8 are the same because of the temperature distribution conditions, the spring reaction forces of both bellows may be the same when the bellows are moved the same. When the shrinkage movement of the bellows 4 and the bellows 8 is always the same as the movement due to the thermal expansion of the equipment nozzle 6 and all the pipe sections, the spring reaction forces of the bellows always cancel each other and therefore the equipment nozzle 6 The spring reaction force of the bellows is prevented from being applied. Therefore, in equation (2), the bellows (4, 8) is the same movement, and ΔLB2 can be replaced by ΔLB1. Therefore, the following equation (3) can be established.

As described above, the distance LT0 between the upper end of the tie rod support flange 10 and the lower end of the tie rod support flange 11 is longer than the conventional bellows type expansion joint of the pressure balance type. This is set in equation (2) so that the total amount of movement of the thermal expansion on the left side is set large, and the ΔLB2 value becomes positive (that is, shrinkage) as in the case of ΔLB1. It is appropriate to adjust the size of LT3 in FIG. 1 to fit the length of this gap with the equation.

When ΔLB1 is deleted from Equations 1 and 3 to derive an equation for calculating LT3, the following Equation 4 is established.

In the piping system according to the exemplary embodiment shown in FIG. 1, providing the magnitude of LT3 calculated by equation (4) is due to the movement D1 (only in the vertical direction) due to thermal expansion of the equipment nozzle 6 caused by the temperature change. It is possible to offset the absorption of the movement of the equipment nozzle 6 and the spring reaction force of the bellows 4, 8 in this case. The piping system according to a typical embodiment has a pressure balanced bellows type expansion joint structure, so that the internal pressure thrust generated by the internal pressure can also be offset. As a result, the external force exerted from the piping system of the equipment nozzle can be suppressed as much as possible.

An example of calculation is as follows.

D1 = 50 [millimeters]

L1 = 500 [mm]

LT1 = LT2 = LT4 = 500 [mm]

LB1 = LNB2 = 1,000 [millimeters]

α _(t) = 0.01392 [-] (when the pipe material is stainless steel 304H and when the temperature varies from about 20 ° C to about 750 ° C)

LT3 = 2? 50 / 0.01392 + 2? 500 + 500 + 500-500 = 8684 [mm]

LT0 = 500 + 1000 + 500 + 8684 + 1000 + 500 = 12184 [mm]

ΔLB1 = ΔLB2 = 50 + 0.01392? (500 + 500 + 500) = 71 [millimeters]

In a piping system according to a typical embodiment, the elbow pipe is used as the main pipe. However, a tee can be used instead.

Equations 1, 2, 3 and 4 were derived on the assumption that the coefficients of thermal expansion of each pipe portion were all equal to α _(t) . The more general equations 5, 6, 7, 8 and 9, which can also deal with the case of different coefficients of thermal expansion due to temperature and material mismatch between pipe sections, are as follows. In the equation, the coefficient of thermal expansion at each pipe portion is, for example, α _{( L1 , t)} in the size L1 of the upright pipe 5 shown in FIG. 5.

When the bellows differ in temperature and material, the theory that the spring reaction force of the bellows is the same when the bellows movement is the same has not been established. Therefore, the spring constant of the bellows at each temperature and the increase in the spring reaction force caused by the thermal expansion of the bellows itself must be taken into account. For this reason, the condition when the bellows 4 and the bellows 8 are equal in the spring reaction force can be given by the following equation.

In equation (7), the direction of the tie rod support flange 10 (upward in FIG. 1) in which the adjustment force F is seen at the equipment nozzle is set to a positive amount. When the spring reaction forces of the bellows 4 and the bellows 8 are completely equal in equilibrium, the adjustment force F is zero. The value is used when the equilibrium is broken and the spring reaction force equilibrates by taking into account friction or hanger resistance.

When ΔLB2 is deleted from equations (6) and (7), the following equation (8) is obtained.

When DELTA LB1 is deleted from equations (8) and (5), and LT3 remains on the left side, the following equation (9) is obtained.

(Another embodiment)

The piping system shown in FIG. 1 is configured such that the main pipe bellows 4 and the pressure balanced bellows 8 are located on a vertical straight line, the pipe extends from the equipment nozzle 6 and the elbow pipe (for bending in the horizontal direction). 1) bent at However, the pipe can extend straight in the vertical direction without bending. 2 and 3 show a piping system configured straight in the vertical direction. Components of FIGS. 2 and 3 that have the same functionality as those shown in FIG. 1 are designated with the same reference numerals.

Referring to FIG. 2, the upright pipe 21 arranged in the vertical direction (vertical direction shown in FIG. 2) has an injection end 2 and an outlet end 3. The discharge end 3 of the upright pipe 21 is connected to a pipe extending in the vertical direction. The injection end 2 of the upright pipe 21 is connected to the upright pipe 5 via a bellows (main pipe bellows 4). The upright pipe 5 is connected to the equipment nozzle 6. The upright pipe 7 is welded to the upper surface of the upright pipe 21 in order to extend in the direction perpendicular to the extending direction of the upright pipe 21. The upright pipe 7 communicates with the interior of the upright pipe 21. The upright pipe 9 is connected to the end of the upright pipe 7 opposite the upright pipe 21 via a bellows (pressure balanced bellows 8) having the same diameter as the bellows 4. The upright pipes 5, 9 each comprise a tie rod support flange 10, 11. A plurality of tie rods 12A arranged at equal intervals are connected to the tie rod support flange 10, and a plurality of tie rods 12B arranged at the same interval are connected to the tie rod support flange 11. The tie rod 12A and the tie rod 12B extend in the direction perpendicular to each other and are connected to the cam plate 25 fitted to the shaft attached to the tie plate 22 disposed on the upright pipe 21. Therefore, even if the bellows (main pipe bellows 4) and bellows (pressure balanced bellows 8) are not in a straight line, their internal pressure thrust can be balanced. The difference in size between the thermally expanding upstanding pipe 21 and the non-thermally expanding tie rod 12A can be transmitted to the tie rod support flange 11 by the rotating cam plate 25. However, the tie plate 22 is fixed to the upright pipe 21 and must be strong enough to be subjected to a force that changes the direction of the internal pressure thrust generated by the internal pressure. In order to maintain the application of equations (2), (3) and (4), the tie plate 22 is insulated to suppress thermal expansion with respect to the temperature of the upright pipe 21, and the length of the LT02 should be kept unchanged.

The upright pipe portion of the upright pipe 21 close to the bellows 4 is connected to the anchor 13. This joint is set to a place where no external force moves (fixed point). As shown in FIG. 1, the anchor 13 is fixed by a section steel structure directly fixed to the concrete base on which the equipment 14 is installed.

Therefore, in the piping system, as in the example shown in FIG. 1, the spring reaction force of the bellows can be canceled by adjusting the size of the pipe portion.

In the example shown in FIG. 2, the magnitude LT3 of equation 4 corresponds to LT31 + LT32: LT31 from the fixed point (anchor 13) to the axis of rotation of the tie plate 22 (center of the cam plate 25) Is the length of the pipe portion of [mm], and LT32 is the second from one of the axis of rotation 25 of the tie plate 22 (center of the left cam plate 25 shown in FIG. 2) close to the second bellows 8; Length [mm] to the connecting end of the bellows and the second pipe member 7. In other words, the size LT31 and the size LT32 can be determined by appropriately dividing the calculation result of the right side (2? D1 /? _(T) + 2? L1 + LT1 + LT2-LT4) of the equation (4). By constructing the piping system shown in FIG. 2 using LT31 and LT32 of the determined size, the equipment nozzle (for the vertical direction only) with respect to movement due to thermal expansion of the equipment nozzle 6 generated by the temperature change, The movement of 6) can be canceled and the spring reaction force of the bellows 4 can be canceled at the same time. This piping system also has a pressure balanced bellows type expansion joint structure, so that the internal pressure thrust generated by the internal pressure can be offset. As a result, the external force exerted from the piping system to the equipment nozzle can be reduced as much as possible.

When the temperature distribution of the piping system is uniform and the spring constants of the bellows 4 and the bellows 8 are equal to each other, the size of the LT31 is calculated by the following equation (10).

When the pipe portion temperature or material that has a thermal expansion coefficient different from the not the same, the size of the LT31 is calculated by the following equation (11) for (Equation 6 α _{(LT3t, t)?} A LT3 α _{(LT31, t)?} LT31 + α _{( LT32 , t)} -calculated by replacing LT32).

Another example of a pipe extending straight in the vertical direction is a piping system comprising a plurality of pressure balanced bellows shown in FIG. 3.

Pulleys and chains may be used in place of the cam plate 25 and tie rods 12A, 12B. All tie rods may be replaced with a chain, or some tie rods may be replaced with a chain.

With reference to FIG. 3, the support plate 23 is welded to the upper surface of the upright pipe 21 so as to extend in a direction perpendicular to the extending direction of the upright pipe 21. Two pipes 7 are fixed to the upper surface of the support plate 23 and arranged to sandwich the upstanding pipe 21 in parallel. Each upright pipe 7 communicates with the inside of the upright pipe 7 via each conductor 24.

The upright pipe 9 has the same bellows (pressure balance) with the same cross-sectional area (i.e. the same internal pressure reaction force) and the same bellows spring reaction force acting on the bellows 4 at the sum of the two places on both sides of the upright pipe 21. It is connected via the bellows 8 to the end of each pipe 7 opposite the support plate 23. To be more specific for better understanding, the single bellows 8 has a cross-sectional area 1/2 times larger than the cross-sectional area of the bellows 4, and therefore its diameter is 1 / √2 times larger (actual bellows diameter: of bellows). Median diameter between the bottom and the vertex). When the bellows cross-sectional shapes are similar, the spring constant is nearly 1√2 times larger in proportion to this diameter. Thus, by adjusting the bell-bottom height of the bellows to be large and setting the spring constant to be one half times larger than the spring constant of the bellows 4, the bellows 4 is provided by the bellows 8 in two places. And equilibrium may be maintained. The upright pipes 5, 9 each comprise a tie rod support flange 10, 11. The two tie rod support flanges 10, 11 are connected to each other by a plurality of tie rods 12 arranged at the same distance and the same length. The upright pipe portion of the upright pipe 21 close to the bellows 4 is connected to the anchor 13. This joint is set to a place (fixed point) which is not moved by any external force. As shown in FIG. 1, the anchor 13 is fixed by a section steel structure directly fixed to the concrete base on which the equipment 14 is installed.

Therefore, in the piping system, by using Equations 10 and 11, the spring reaction force of the bellows can be offset by adjusting the size of the pipe portion. In this piping system, there is no link type cam plate similar to that shown in Fig. 2, and thus the frictional force and the resistance are further reduced.

However, in FIG. 3, it communicates with the upright pipes 7, 9 via a conductor 24 having a smaller diameter than the upright pipe 21, and the structure is closed past the upright pipes 7, 9. Therefore, the flow of internal fluid stops here. The flow structure of the heat conducted from the upright pipe 21 through the pipe member is smaller than that shown in FIGS. 1 and 2, and therefore it is difficult to keep the temperature between the upright pipes 7, 9 and the upright pipe 21 the same. it's difficult. This requires using a value of the coefficient of thermal expansion α _{(t) that} is different from the coefficient of thermal expansion of the upright pipe 21. For example, when the temperatures of the upright pipes 7 and 9 and the bellows 8 do not increase, there is no thermal expansion, and α _{( LT32 , t)} , α _{( LB2 , t)} and α _{( LT4 , t)} Equation 11 becomes 0. Accordingly, the equation is simplified, and the size of the LT31 is calculated by the following equation (12).

When the upright pipes 5, 21 have the same temperature, material, and coefficient of thermal expansion, α _{( L1 , t)} , α _{( LT1 , t)} , α _{( LT2 , t)} , and α _{( LT31 , t)} are equal Do. Therefore, by using α _{( L1 , t)} as a representative, the magnitude of LT31 is calculated by the following equation (13).

1 to 3 show no hanger support, for example, an upright pipe 5 and tie rod support flange 10, pressure balanced bellows, located below the bellows 4 in FIG. (8) The weight of the upright pipe (9) and tie rod support flange (11), and tie rod (12) located above should be lifted by spring support (or a constant spring hanger with smaller load fluctuations caused by movement). . The piping system should be supported at the center of the pipe height when used as a horizontal pipe. In this case, friction and actuation resistance should be reduced as much as possible. This pipe support is not shown for simplicity.

The installation of such constant spring hangers requires an initial load inspection of the constant spring hangers. However, according to the invention, the pipe member on the bellows 4 is fixed by the anchor 13 so as not to move. Therefore, the load lifted by a constant spring hanger to relieve the load at the equipment nozzle 6 is limited to the tie rod 12 and the pipe member connected by the tie rod. The load of the pipe connected to the main pipe and the main pipe, such as the elbow pipe 1 and the upright pipe 12, is supported by the anchor 13. Thus, the load is much less than that when a constant spring hanger lifts most of the overall piping system of a conventional type of piping system, and the initial load of the constant spring hanger can be much lessened. As a result, even when the diameter of the pipe is made larger by increasing the pipe load, the load on the equipment nozzle can be reduced even more than in a conventional piping system.

Exemplary embodiments of the invention have been described with reference to the accompanying drawings. However, the present invention is not limited to piping systems connected in the equipment nozzle 6 extending vertically (in the vertical direction) as shown. The piping system of the present invention can be applied to the direction of extension of the equipment nozzle.

While the preferred embodiments of the present invention have been described using specific terms, such techniques are for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the scope or spirit of the following claims. I understand.

1 elbow pipe (main pipe described in claim)
2 input terminal
3 discharge terminal
4 bellows (first bellows as set forth in claim)
5 straight pipe (first piping member described in claim)
6 equipment nozzle
7 upright pipe (second piping member described in claim)
8 pressure balanced type bellows (second bellow as described in claim)
9 upright pipe (third piping member described in claim)
10, 11 tie rod support flange (tie rod support member described in claim)
12, 12A, 12B tie rod
13 anchor (fixed point)
14 equipment
15 equipment fixed point
21 Upright pipe (main pipe as described in claim)
22 link type tie plate (link described in claim)
23 support plate
24 conductor (second piping member described in claim)
25 cam plate

Claims (9)

Piping system,
Bellows type expansion joints connected to the equipment nozzles of the equipment;
Main pipe;
A first pipe member connected to an equipment nozzle extending from the equipment and connected to one end of the main pipe through a first bellows;
A second pipe member, one end of which is connected to the side portion of the main pipe;
A third pipe member connected to the other end of the second pipe member through a second bellows;
A first tie rod support member (flange) fixed around the outside of the first pipe member;
A second tie rod support member (flange) fixed around the outside of the third pipe member;
A tie rod for maintaining a predetermined distance between the first tie rod support member and the second tie rod support member; And
An anchor disposed to set the main pipe portion near the first bellows as a fixed point,
The length of the pipe member between the first tie rod support member and the second tie rod support member is determined such that the first bellows is closer to the equipment nozzle than the thermal expansion of the equipment nozzle, the thermal expansion of the first pipe member, and the anchor. A piping system which contracts by thermal expansion of a pipe member of a main pipe, and the second bellows is contracted by thermal expansion of all pipe members between the first and second tie rod support members to move (shrinkage) in the same manner as the first bellows. The method of claim 1,
Expression

here,
D1: amount of movement [mm] caused by the temperature change of the equipment nozzle,
L1: length of the first pipe member portion from the connection end with the equipment nozzle to the first tie rod support member [mm],
α _{( L1 , t)} : coefficient of thermal expansion when the temperature changes from room temperature to the specified temperature of the first pipe member portion from the connecting end with the equipment nozzle to the first tie rod support member,
LT1: length of the first pipe member portion from the end of the first tie rod support member opposite the equipment nozzle side to the first bellows [mm],
α _{( LT1 , t)} : coefficient of thermal expansion at the time of temperature change from the end of the first tie rod support member opposite the equipment nozzle side to the specific temperature of the first pipe member portion from the first bellows,
LT2: length of the pipe section of the main pipe from the connecting end of the first bellows and the main pipe to the anchor [mm],
α _{( LT2 , t)} : coefficient of thermal expansion at the time of temperature change from room temperature to a specific temperature of the pipe part of the main pipe from the connecting end of the first bellows and the main pipe to the anchor,
LT3: length of the pipe section from the anchor to the second bellows [mm],
α _{( LT3 , t)} : coefficient of thermal expansion at the time of temperature change from room temperature to a specific temperature of the pipe region from the anchor to the second bellows,
LT4: length of the third pipe member part from the connecting end of the second bellows and the third pipe member to the end of the second tie rod supporting member on the equipment nozzle side [mm],
α _{( LT4 , t)} : heat at the time of temperature change from the connecting end of the second bellows and the third pipe member to the specific temperature of the third pipe member portion from the end of the second tie rod support member on the equipment nozzle side Coefficient of expansion,
k _{(B1, t)} : spring constant [N / mm], at a specific temperature of the first bellows,
k _{(B2, t)} : spring constant [N / mm] at a specific temperature of the second bellows, and
F [N]: Adjustment force for lifting the piping system
Piping system to satisfy. The piping system according to claim 1 or 2, wherein the main pipe is an elbow pipe or a tee. The piping system of claim 1, wherein the main pipe comprises an upright pipe. The method of claim 4, wherein
The second pipe member is connected to the side face of the main pipe opposite the equipment nozzle side of the anchor and extends in a direction having a predetermined angle in the extending direction of the main pipe, the tie rod being the tie plate. And piping systems arranged at an angle by use of a cam plate. The method of claim 5, wherein
Expression

here,
D1: amount of movement [mm] caused by the temperature change of the equipment nozzle,
L1: length of the first pipe member portion from the connection end with the equipment nozzle to the first tie rod support member [mm],
α _{( L1 , t)} : coefficient of thermal expansion when the temperature changes from room temperature to the specified temperature of the first pipe member portion from the connecting end with the equipment nozzle to the first tie rod support member,
LT1: length of the first pipe member portion from the end of the first tie rod support member opposite the equipment nozzle side to the first bellows [mm],
α _{( LT1 , t)} : coefficient of thermal expansion at the time of temperature change from the end of the first tie rod support member opposite the equipment nozzle side to the specific temperature of the first pipe member portion from the first bellows,
LT2: length of the pipe section of the main pipe from the connecting end of the first bellows and the main pipe to the anchor [mm],
α _{( LT2 , t)} : coefficient of thermal expansion at the time of temperature change from room temperature to a specific temperature of the pipe part of the main pipe from the connecting end of the first bellows and the main pipe to the anchor,
LT31: pipe portion from the anchor to the axis of rotation disposed on the tie plate, the length of the portion contained in the pipe portion from the anchor to the second bellows [mm],
α _{( LT31 , t)} : pipe portion from the anchor to the axis of rotation disposed on the tie plate, the coefficient of thermal expansion at the time of temperature change from the anchor to the specific temperature of the portion contained in the pipe portion from the anchor to the second bellows,
LT32: Length of the part contained in the pipe part from the anchor to the second bellows, as a part of the tie plate, located from the axis of rotation close to the second bellows to the connecting end of the second pipe member and the second bellows [mm] ,
α _{( LT32 , t)} : a portion disposed in the tie plate and a portion from the axis of rotation close to the second bellows to the connecting end of the second pipe member and the second bellows, the portion contained in the pipe portion from the anchor to the second bellows. Coefficient of thermal expansion when the temperature changes from room temperature to a specific temperature of
LT4: length of the third pipe member part from the connecting end of the second bellows and the third pipe member to the end of the second tie rod supporting member on the equipment nozzle side [mm],
α _{( LT4 , t)} : heat at the time of temperature change from the connecting end of the second bellows and the third pipe member to the specific temperature of the third pipe member portion from the end of the second tie rod support member on the equipment nozzle side Coefficient of expansion,
k _{(B1, t)} : spring constant [N / mm], at a specific temperature of the first bellows,
k _{(B2, t)} : spring constant [N / mm] at a specific temperature of the second bellows, and
F [N]: Adjustment force for lifting the piping system
Piping system to satisfy. 7. Piping system according to claim 5 or 6, wherein pulleys and chains are used in place of some or all of the tie rods and the cam plate. 5. The apparatus of claim 4, further comprising a support plate fixed to the side of the main pipe and extending in a direction perpendicular to the extension direction of the main pipe,
One end of the second pipe member is connected to the side of the support plate opposite the equipment nozzle side, at least two of the second pipe members are arranged parallel to each other in the main pipe, and the effective diameter of the second bellows Piping system equal to the area at the effective diameter of the first bellows. The method of claim 8,
Expression

here,
D1: amount of movement [mm] caused by the temperature change of the equipment nozzle,
L1: length of the first pipe member portion from the connection end with the equipment nozzle to the first tie rod support member [mm],
α _{( L1 , t)} : coefficient of thermal expansion when the temperature changes from room temperature to the specified temperature of the first pipe member portion from the connecting end with the equipment nozzle to the first tie rod support member,
LT1: length of the first pipe member portion from the end of the first tie rod support member opposite the equipment nozzle side to the first bellows [mm],
α _{( LT1 , t)} : coefficient of thermal expansion at the time of temperature change from the end of the first tie rod support member opposite the equipment nozzle side to the specific temperature of the first pipe member portion from the first bellows,
LT2: length of the pipe section of the main pipe from the connecting end of the first bellows and the main pipe to the anchor [mm],
α _{( LT2 , t)} : coefficient of thermal expansion at the time of temperature change from room temperature to a specific temperature of the pipe part of the main pipe from the connecting end of the first bellows and the main pipe to the anchor,
LT31: the portion from the anchor to the support member for fixing the second pipe member to the main pipe, the length of the portion contained in the pipe portion from the anchor to the second bellows [mm],
α _{( LT31 , t)} : the portion from the anchor to the support member for fixing the second pipe member to the main pipe, wherein the temperature change of the ambient temperature from the anchor to the specific temperature of the portion contained in the pipe portion from the second bellows Thermal expansion coefficient,
LT32: length from the support member to the second bellows for securing the second pipe member to the main pipe, the length of the portion contained in the pipe portion from the anchor to the second bellows [mm],
α _{( LT32 , t)} : the _temperature from the support member to the second bellows for fixing the second pipe member to the main pipe, and the temperature at room temperature to a specific temperature of the portion contained in the pipe portion from the anchor to the second bellows. Coefficient of thermal expansion at change,
LT4: length of the third pipe member part from the connecting end of the second bellows and the third pipe member to the end of the second tie rod supporting member on the equipment nozzle side [mm],
α _{( LT4 , t)} : thermal expansion at normal temperature change from the connecting end of the second bellows and the third pipe member to the specific temperature of the third pipe member from the end of the second tie rod support member on the equipment nozzle side Coefficient,
k _{(B1, t)} : spring constant [N / mm], at a specific temperature of the first bellows,
k _{(B2, t)} : spring constant [N / mm] at a specific temperature of the second bellows, and
F [N]: Adjustment force for lifting the piping system
Piping system to satisfy.

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